Nanoporous spongy graphene: Potential applications for hydrogen adsorption and selective gas separation
Nanoporous spongy graphene: Potential applications for hydrogen adsorption and selective gas separation
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DOI：
10.1016/j.tsf.2015.06.060
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发表时间：
2015-12-01
期刊：
影响因子：
2.1
通讯作者：
Rebholz, Claus
中科院分区：
文献类型：
--
作者：
Kostoglou, Nikolaos;Constantinides, Georgios;Rebholz, Claus
在本研究中，通过氧化石墨烯的湿化学还原与冷冻干燥相结合，合成了一种具有大表面积（约350 m(2)/g）的纳米多孔（孔径约0.7 nm）石墨烯基海绵状材料。采用扫描电镜和透射电镜结合能量色散x射线能谱仪对表面形貌和元素组成进行了研究。采用傅里叶变换红外光谱对其表面化学进行定性分析，并用x射线衍射分析对其结构进行表征。根据在77 K和高达1 bar条件下获得的氮气吸附/解吸数据，推导出了结构特性，包括Brunauer-Emmet-Teller （BET）表面积、微孔体积和表面积以及孔径分布。通过不同温度（77,273和298 K）下的低压（0-1 bar） H-2、CO2和CH4吸附测量，初步评估了海绵石墨烯在气体储存和分离应用中的潜在用途。利用Clausius-Clapeyron方程计算了CO2 （28-33 kJ/mol）和CH4 （30-38 kJ/mol）的等容吸附焓，利用理想吸附溶液理论（IAST）估计了CO2/CH4气体的选择性（高达95:1）。(C) 2015 Elsevier B.V.版权所有
In the present work, a nanoporous (pore width similar to 0.7 nm) graphene-based sponge-like material with large surface area (similar to 350 m(2)/g) was synthesized by wet chemical reduction of graphene oxide in combination with freeze-drying. Surface morphology and elemental composition were studied by scanning and transmission electron microscopy combined with energy dispersive X-ray spectroscopy. Surface chemistry was qualitatively examined by Fourier-transform infrared spectroscopy, while the respective structure was investigated by X-ray diffraction analysis. Textural properties, including Brunauer-Emmet-Teller (BET) surface area, micropore volume and surface area as well as pore size distribution, were deduced from nitrogen gas adsorption/desorption data obtained at 77 K and up to 1 bar. Potential use of the spongy graphene for gas storage and separation applications was preliminarily assessed by low-pressure (0-1 bar) H-2, CO2 and CH4 sorption measurements at different temperatures (77, 273 and 298 K). The adsorption capacities for each gas were evaluated up to similar to 1 bar, the isosteric enthalpies of adsorption for CO2 (28-33 kJ/mol) and CH4 (30-38 kJ/mol) were calculated using the Clausius-Clapeyron equation, while the CO2/CH4 gas selectivity (up to 95:1) was estimated using the Ideal Adsorbed Solution Theory (IAST). (C) 2015 Elsevier B.V. All rights reserved.